Conventionally, as a safety case in which an electronic component requiring security is accommodated, a safety case has been known which is capable of detecting illegal access to the safety case and preventing leakage of data held by the electronic component (see, for example, Patent Literature 1). The safety case described in Patent Literature 1 is structured of an upper wall part in a flat plate shape, a side wall part in a tube shape, and a lower wall part in a flat plate shape. The upper wall part and the lower wall part are structured of an outer wall layer, a breakage detection layer and a circuit board layer which are disposed from an outer side of the safety case in this order. The outer wall part is a layer exposed to an outer side of the safety case and is a circuit board on which an electronic component requiring no security is mounted. The circuit board layer is a circuit board on which an electronic component requiring security is mounted.
In the safety case described in Patent Literature 1, the breakage detection layer structuring the upper wall part and the lower wall part includes an insulating base member and wiring patterns formed on both faces of the base member. The wiring pattern is structured of a plurality of base units in a spiral shape each of which is formed so that one detection line and ground lines interposing the detection line from both sides are wound in a spiral shape and covers entire regions of both faces of the base member. In the safety case, when the upper wall part or the lower wall part is broken, the wiring pattern of the breakage detection layer is disconnected and the disconnection of the wiring pattern is detected. Further, in the safety case, a predetermined processing is executed when disconnection of the wiring pattern is detected and thereby data leakage held by the electronic component is prevented.